In the fabrication of semiconductor integrated circuits, metal conductor lines are used to interconnect the multiple components in device circuits on a semiconductor wafer. A general process used in the deposition of metal conductor line patterns on semiconductor wafers includes deposition of a conducting layer on the silicon wafer substrate; formation of a photoresist or other mask such as titanium oxide or silicon oxide, in the form of the desired metal conductor line pattern, using standard lithographic techniques; subjecting the wafer substrate to a dry etching process to remove the conducting layer from the areas not covered by the mask, thereby leaving the metal layer in the form of the masked conductor line pattern; and removing the mask layer typically using reactive plasma and chlorine gas, thereby exposing the top surface of the metal conductor lines. Typically, multiple alternating layers of electrically conductive and insulative materials are sequentially deposited on the wafer substrate, and conductive layers at different levels on the wafer may be electrically connected to each other by etching vias, or openings, in the insulative layers and filling the vias using aluminum, tungsten or other metal to establish electrical connection between the conductive layers.
Normally in etchers and other semiconductor processing tools such as those used for the deposition of thin films on wafers, gases in the form of chemicals or fluids are injected or flowed towards the wafer surface for etching or deposition purposes. The direction of flow and distribution of the fluid on the wafer surface influences the etching rate or deposition rate, as well as the CD (critical dimension) uniformity or film thickness uniformity. Conventional processing tools use a fixed-type fluid injector or plate which provides flow of the fluid against the wafer in a fixed direction or distribution pattern. Therefore, under circumstances in which there exists a need to adjust the flow and distribution of the fluid on the wafer surface for purposes of etching or deposition uniformity, such tools are unsuitable. Therefore, a new and improved fluid injection apparatus is needed to facilitate flow of processing fluids against a wafer surface in various flow and distribution patterns depending on the particular processing requirements.